Add ssl_get_client_min_max_version() function

Adjust ssl_set_client_hello_version to get both the minimum and maximum and then
make ssl_set_client_hello_version use the maximum version.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>

MR: 
This commit is contained in:
Kurt Roeckx 2016-02-07 20:07:21 +01:00
parent b11836a63a
commit 068c358ac3
2 changed files with 44 additions and 18 deletions

View file

@ -1986,6 +1986,7 @@ __owur int ssl_check_version_downgrade(SSL *s);
__owur int ssl_set_version_bound(int method_version, int version, int *bound);
__owur int ssl_choose_server_version(SSL *s);
__owur int ssl_choose_client_version(SSL *s, int version);
int ssl_get_client_min_max_version(const SSL *s, int *min_version, int *max_version);
__owur long tls1_default_timeout(void);
__owur int dtls1_do_write(SSL *s, int type);

View file

@ -693,7 +693,7 @@ int ssl_allow_compression(SSL *s)
return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
}
static int version_cmp(SSL *s, int a, int b)
static int version_cmp(const SSL *s, int a, int b)
{
int dtls = SSL_IS_DTLS(s);
@ -764,7 +764,7 @@ static const version_info dtls_version_table[] = {
*
* Returns 0 on success, or an SSL error reason on failure.
*/
static int ssl_method_error(SSL *s, const SSL_METHOD *method)
static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
{
int version = method->version;
@ -1006,23 +1006,26 @@ int ssl_choose_client_version(SSL *s, int version)
return SSL_R_UNSUPPORTED_PROTOCOL;
}
/*-
* ssl_set_client_hello_version - Work out what version we should be using for
* the initial ClientHello if the version is initially (D)TLS_ANY_VERSION. We
* apply any explicit SSL_OP_NO_xxx options, the MinProtocol and MaxProtocol
* configuration commands, any Suite B or FIPS_mode() constraints and any floor
* imposed by the security level here, so we don't advertise the wrong protocol
* version to only reject the outcome later.
/*
* ssl_get_client_min_max_version - get minimum and maximum client version
* @s: The SSL connection
* @min_version: The minimum supported version
* @max_version: The maximum supported version
*
* Work out what version we should be using for the initial ClientHello if the
* version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
* options, the MinProtocol and MaxProtocol configuration commands, any Suite B
* or FIPS_mode() constraints and any floor imposed by the security level here,
* so we don't advertise the wrong protocol version to only reject the outcome later.
*
* Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
* TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
* only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
*
* @s: client SSL handle.
*
* Returns 0 on success or an SSL error reason number on failure.
* Returns 0 on success or an SSL error reason number on failure. On failure
* min_version and max_version will also be set to 0.
*/
int ssl_set_client_hello_version(SSL *s)
int ssl_get_client_min_max_version(const SSL *s, int *min_version, int *max_version)
{
int version;
int hole;
@ -1040,7 +1043,7 @@ int ssl_set_client_hello_version(SSL *s)
* versions they don't want. If not, then easy to fix, just return
* ssl_method_error(s, s->method)
*/
s->client_version = s->version;
*min_version = *max_version = s->version;
return 0;
case TLS_ANY_VERSION:
table = tls_version_table;
@ -1071,7 +1074,7 @@ int ssl_set_client_hello_version(SSL *s)
* If we again hit an enabled method after the new hole, it becomes
* selected, as we start from scratch.
*/
version = 0;
*min_version = version = 0;
hole = 1;
for (vent = table; vent->version != 0; ++vent) {
/*
@ -1087,18 +1090,40 @@ int ssl_set_client_hello_version(SSL *s)
hole = 1;
} else if (!hole) {
single = NULL;
*min_version = method->version;
} else {
version = (single = method)->version;
*min_version = version;
hole = 0;
}
}
*max_version = version;
/* Fail if everything is disabled */
if (version == 0)
return SSL_R_NO_PROTOCOLS_AVAILABLE;
if (single != NULL)
s->method = single;
s->client_version = s->version = version;
return 0;
}
/*
* ssl_set_client_hello_version - Work out what version we should be using for
* the initial ClientHello.
*
* @s: client SSL handle.
*
* Returns 0 on success or an SSL error reason number on failure.
*/
int ssl_set_client_hello_version(SSL *s)
{
int min, max, ret;
ret = ssl_get_client_min_max_version(s, &min, &max);
if (ret != 0)
return ret;
s->client_version = s->version = max;
return 0;
}